John Isner came back from looking down and out to win his semi-final at the Heineken Open today against Roberto Bautista Agut.

The tournament's third seed won 3-6 7-6 6-4 in one hour 50 minutes, but when his Spanish opponent was serving for the match in the second set having won the third it looked like the American's time in Auckland was coming to an end.

But from that game on, when he managed to get the set back to 5-5, Isner was a changed man.

No longer was he appearing lethargic around the court and over casual with his shots. He fought for the first time in the match Isner looked inspired and hungry.

Few people would have known much about the 25-year-old Spaniard before this tournament began and his two previous appearances at this tournament he has failed to make it out of the qualifying event.

But the world No 73 has proved himself to be a gutsy battler over the week and should expect to make a decent climb up the rankings over 2014.

How Isner finished the match couldn't have been in more contrast to how he started it.

The world No 14 just couldn't get going in the first set and was broken twice. Each time he had a break point against him he failed to hold serve, conversely the Spaniard was able to fend off the only break point against him.

Bautista Agut got a break in the third game of the next set as Isner looked like he already had one foot on the plane to Melbourne.

In the sixth game Isner was able to get himself up 0-40 on Bautista Agut's serve but once again there were a number of poor shots from him, while his opponent was content to just keep getting the ball back and wait for Isner's mistake.

There was to be one final twist though as when Bautista Agut was serving for the match he was broken and from there, it was all Isner.